Have a minus to academic doesn't make you a mage. Doing 10 (or whatever) would only be at high levels. The idea was that when you take your sword out (a last resort) you can't resist magic, regen, dodge or do anything else you might do with chi: you end up able to call high damage but that's it.
The problem I see with that is that in 90% of cases, you'll never use your sword as a last resort, because in a "last resort" situation, being able to dodge, regen and resist magic is much, much more useful than 3 or 4 extra damage grades. Nine time out of ten, I'd say. In my opinion you'd only ever see a Shaded Blade draw their sword to show off a bit.
I know that's what it's sort of supposed to be for, but I just think when you see a Shaded Blade unshade their sword, people should think "Okay, now we're in trouble. Sh*t is about to go down", and then they watch the Shaded Blade have his moment of glory holding off three monsters or whatever, instead of watching him call a high damage grade once and then die to a monster with a shield calling quad.